The materials used in the papermaking field, textile field and the like generally comprise impurities like gooey, grease, paraffin, plastic, etc. which can reduce the quality of fiber products, so it's necessary to remove them during the manufacturing processes.
The impurities in the materials are generally mixed with fibers, so the key step during the impurities removal is to strip impurities from fiber. In existing technology, The Chinese patent CN2711215Y adopting a hydrapulper to remove impurities disclosed a twin scroll hydrapulper, comprising a tub, a feed port, a reducer, a disk-cutter, a sieve plate, a discharge port for impurities, a discharge port for pulp and a motor. The cutter shafts driven by the motor are crossly arranged on the two sides of the tub in parallel, the disk-cutters are arranged thereon; the sieve plates are arranged on the outside of the disk-cutters; the reducer arranged between the cutter shaft and the motor has an meshing spiral bevel gear arranged therein. Two pulping units, filter units and discharge ports are arranged on two sides of the twin scroll hydrapulper, and the two pulping units generating twin scroll interaction are arranged on different side and not coaxial, but rotate with the same speed and direction. When hydrapulper is running, the pulp led by the disk-cutters moves fast and the impurities on fiber are stripped by the interaction generated by the relative motion of the pulp and fiber, however, a small interaction force is generated because of the low speed of the relative motion, so the impurities on fiber cannot be removed effectively. A higher speed of the disc-cutters required to move the pulp fast leads to a high power consumption and goes against cost reduction.
Different kinds of heat dispersion machines are always used as a supplement of the hydrapulper for stripping the impurities on fiber which is applied in the Chinese patent CN2839340, a heat dispersion machine is disclosed therein, comprising a motor, a body having a discharge port, a stationary disc and a rotating disc arranged thereon, a feed system having a feed port arranged thereon and a base, wherein, a drive shaft having a rotating disc connected thereon fixedly connects with the motor shaft arranged on the motor. When the heat dispersion machine is running, fiber in the pulp is rubbing and moving by the cooperation of the stationary disc and the rotating disc to remove the impurities from the fiber. In order to have a sufficient contact of fibers, the pulp used in the heat dispersion machine has a high concentration which increases the running resistance, and an associated machine is used to concentrate the pulp suspension in advance which wastes lots of energy; in addition, the heat dispersion machine is generally used with the cooperation of chemical additives at high temperatures to resolve the impurities in the pulp having high concentration, which not only effects the performance of fiber, but also causes a lot of pollution.
To solve the above technical problems, the English patent GB2099325A disclosed a rotary strainer for fibrous pulp suspensions comprising a housing, a fixed cylindrical strainer arranged therein, an annular strainer chamber formed between the housing and the strainer, blades which rotate relative to the strainer basket about a substantially vertical axis arranged in the strainer and a pulp inlet arranged on the housing. The fibrous pulp suspension is supplied to the annular strainer chamber which narrows continuously in the flow direction from the same cross-section so as to avoid of the extraction of long fibers along with the waste matter from the outlet for impurities.
In the above technology, the strainer strains impurities from fibrous pulp suspensions supplied into the strainer and broken by the blades. This machine has a low consumption of energy and does not require high temperature and the chemical additives, however, the blades are just used for breaking the pulp, but not stripping impurities from fiber, so it cannot remove impurities from fiber effectively.